This invention relates to a random timer, and more particularly to a timer for controlling the operation of a video monitor/recorder device set up to conduct time studies.
Timer systems for controlling the operation of video recorders, and for many other purposes, are commonplace. This timer system was developed for use with a video monitor/recorder device set up to conduct time studies of clean room operations for the purpose of establishing valid labor standards. Originally, the video systems were intended to record continuously, producing a large number of frames representing clean room operations from which a small number of randomly selected frames were used as the sample population for the required statistical studies. This method required large amounts of video tape and manual effort. Samples taken at regular intervals were not acceptable since they tended to introduce bias in personnel work habits. Totally random sampling methods were also rejected since they could not be effectively related to real time without restricting the number of frames per hour, which then could occur within a short time interval leaving a large portion of the hour unmonitored; thereby, making the system predictable.